001package Torello.Java.Function;
002
003import java.util.function.Function;
004
005/**
006 * Function-Pointer
007 * <SPAN CLASS=TJF>Input:</SPAN> {@code int, int, float}
008 * <SPAN CLASS=TJF>Output:</SPAN> {@code R}.
009 * 
010 * <BR /><BR />
011 * Primitive's Extension to Java's {@code java.util.function.*} package.
012 * <BR /><BR />This {@code FunctionalInterface} has an {@code apply(...)} method which accepts
013 * three primitives: two {@code int}-primitives, and one {@code float}.
014 * 
015 * @param <R> The type of the function-output.
016 */
017@FunctionalInterface
018public interface IntIntFloatFunc<R>
019{
020    /**
021     * Applies a user-provided function to input aruments, returning a result of type {@code R}
022     * <BR /><BR /><EMBED CLASS='external-html' DATA-FILE-ID=FUNC_INTER_METH>
023     *
024     * @param i1 The first integer-parameter.
025     * @param i2 The second integer-parameter.
026     * @param f A {@code 'float'} parameter.
027     * @return The function result.  Result shall be of type {@code 'R'}
028     */
029    public R apply(int i1, int i2, float f);
030
031    /**
032     * Returns a composed function that first applies {@code 'this'} function to its input, and
033     * then applies the {@code 'after'} function to the result. If evaluation of either function
034     * throws an exception, it is relayed to the caller of the composed function.
035     * 
036     * @param <V> The output-type of the {@code 'after'} function, and also of the (returned)
037     * {@code 'composed'} function.
038     * 
039     * @param after The function to apply, after this function is applied.
040     * @throws NullPointerException This throws if null is passed to {@code 'after'}.
041     */
042    public default <V> IntIntFloatFunc<V> andThen(Function<R, V> after)
043    {
044        if (after == null) throw new NullPointerException
045            ("null has been passed to parameter 'after'");
046
047        return (int i1, int i2, float f) -> after.apply(this.apply(i1, i2, f));
048    }
049}